Myc protein expression correlates with MYC amplification in small‐cell lung carcinoma. Issue 1 (20th January 2015)

• Record Type: Journal Article
• Authors: Hwang, David H; Sun, Heather; Rodig, Scott J; Hornick, Jason L; Sholl, Lynette M
• Is Part Of: Histopathology. Volume 67:Issue 1(2015)
• Page Start: 81
• Page End: 89
• Publication Date: 2015-01-20
• Subjects: Histology, Pathological -- Periodicals; 611.018
• DOI: 10.1111/his.12622
• Languages: English
• ISSNs: 0309-0167

Abstract

<abstract abstract-type="main" id="his12622-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="his12622-sec-0001" sec-type="section"> <title>Aims</title> <p>Myc family members are important contributors to oncogenesis in a variety of tumours. Identification of therapeutic targets is needed in small‐cell lung carcinoma (SCLC), an aggressive disease with limited treatment options. Sequencing studies have identified <italic>MYC</italic> amplification in 2–7% of SCLCs. This study aims to determine the rate of <italic>MYC</italic> gene amplification and its correlation with Myc protein overexpression in SCLC.</p> </sec> <sec id="his12622-sec-0002" sec-type="section"> <title>Methods and results</title> <p>One hundred and three cases of formalin‐fixed, paraffin‐embedded SCLC were examined. Myc protein expression was scored according to the extent of immunohistochemical staining. <italic>MYC</italic> copy number (CN) was evaluated with dual‐colour chromogenic <italic>in‐situ</italic> hybridization (CISH) for the <italic>MYC</italic> locus and a chromosome 8 (Chr8) centromeric control. Amplification was defined as a <italic>MYC</italic>/Chr8 ratio of ≥2. Thirty‐eight per cent of SCLCs had some degree of Myc protein expression, and 9% of cases were <italic>MYC</italic>‐amplified. <italic>MYC</italic> CN was significantly correlated with the extent of Myc protein expression (Spearman's ρ = 0.57, <italic>P</italic> < 0.01). There was no significant association between Myc expression or CN and clinicopathological features.</p> </sec> <sec id="his12622-sec-0003" sec-type="section"> <title>Conclusions</title> <p> <italic>MYC</italic> amplification by CISH was identified in 9% of SCLCs, and correlated with protein expression. As novel Myc‐targeted therapies are developed, CISH and IHC should be considered as biomarkers of Myc pathway dysregulation in SCLC.</p> </sec> </abstract>